Add a world-state edit mode for overriding live RPG values

Players/authors can now directly correct the live values of stats the
schema already defines (health, trust, flags, milestones, etc.) without
waiting for the AI to emit a delta. New apply_override() sets values
absolutely rather than adding deltas, and — unlike the AI-facing
apply_delta() — bypasses cooldown/max_delta_per_turn and lets
milestones be un-set, since this is a deliberate correction rather
than a turn to police. Exposed via PUT /adventures/{id}/world-state
and an edit toggle in the World State drawer. Also fixes the
schema-editor stat-kind dropdown and free-text initial-value input
to size consistently with the numeric fields next to them.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/SchemaEditor.jsx

@@ -72,7 +72,7 @@ function StatEditor({ statKey, def, onRenameKey, onChange, onRemove }) {
       </div>
       <div className="se-fields">
         {isText ? (
-          <label className="se-num">
+          <label className="se-num se-initial-text">
             <span>initial</span>
             <input type="text" value={def.initial ?? ''}
               onChange={(e) => set('initial', e.target.value)} />